Abstract: Monomicrobial nonneutrocytic bacterascites and spontaneous bacterial peritonitis (SBP), the variants of ascitic fluid infection, are commonly seen in association with liver cirrhosis. Monomicrobial nonneutrocytic bacterascites may progress rapidly to SBP resulting in increased morbidity and mortality in advanced liver cirrhosis with portal hypertension. The most common pathogens associated with both conditions are gram-negative bacilli like Escherichia coli and Klebsiella pneumoniae followed by gram-positive bacteria. We present a case of monomicrobial nonneutrocytic bacterascites in a chronic alcoholic patient with advanced liver cirrhosis, due to an unusual pathogen, Achromobacter xylosoxidans. This case is remarkable as A xylosoxidans is not associated with SBP until now as per available literature.